The weather is hot in summer, and air conditioning is indispensable when driving. Some car owners don't know much about car air conditioners, and may encounter problems of one kind or another during use, some of which are related to operation and some to air conditioner work.
In fact, many problems can be easily solved as long as you know a little bit about car air conditioners. So today we will share some knowledge related to car air conditioners.
1. How does a car air conditioner produce air conditioning?
When strangers interact with each other for the first time, they must get to know each other. If we want to understand the car air conditioner, it is also necessary to have a general understanding of its working principle.
The principle of car air conditioning can actually be described in very simple language. It is that the compressor drives the refrigerant to circulate in the air conditioning pipeline. One part of the air conditioning pipeline is inside the car and the other part is outside the car. The refrigerant changes from liquid to gas in the evaporator inside the car. It vaporizes and absorbs heat to produce low temperature. Then the gaseous refrigerant is compressed by the compressor. It liquefies and releases heat in the condenser outside the car and becomes liquid again. Then it enters the car again. Vaporization absorbs heat. In this way, the heat in the car is transferred to the outside of the car little by little, and the interior of the car is naturally cooler.
Therefore, if you want to make your car's cooling effect better, you must keep the outside condenser and the inside evaporator clean, so as to improve the efficiency of heat exchange.
2. Types of car air conditioning compressors
Although car compressors look similar in appearance, their differences are quite big. At present, air conditioning compressors in household vehicles can be divided into two types according to their structures, one is a piston compressor and the other is a scroll compressor. According to the working mode, it can be divided into fixed displacement compressor and fixed displacement compressor. A piston compressor is much like a car engine, relying on the reciprocating motion of the piston to suck in and compress refrigerant. The mechanical loss of the piston compressor is relatively large, but its structure can achieve variable displacement function through special design. So now many cars are equipped with variable displacement compressors that are piston-type. The mechanical loss of scroll compressors is very small, but the displacement is fixed. Nowadays, fixed-displacement compressors in household vehicles are almost all scroll type, with simple structure and small losses.
3. The air-conditioning compressor does not always run.
For fixed-displacement compressors, the compressor does not always work when driving with the air conditioner on, but works and stops for a while. Because if the compressor keeps working, liquid refrigerant will continue to vaporize and absorb heat in the evaporator, and there is a lot of condensed water on the surface of the evaporator. When the temperature is close to zero, the condensed water will freeze and completely block the evaporator. , the air conditioner will not blow out the air.
Therefore, there is a temperature sensor on the evaporator of the air conditioner. When the evaporator temperature is close to the frost temperature, the compressor clutch will be disconnected. This phenomenon is most obvious when the air conditioner is turned on in situ. Standing outside the car, you can clearly hear the sound of the compressor's electromagnetic clutch constantly closing and disconnecting.
Sometimes when driving, you suddenly feel the car body moving forward, which means the compressor is basically disconnected. And after more than ten seconds, the car body suddenly seemed to be pulled again. This is probably because the compressor was turned on again.
4. The "cheating" temperature adjustment principle
If your car has a fixed displacement compressor, it is most cost-effective to adjust the temperature to the lowest when turning on the air conditioner.
Because this air conditioning system adjusts the air outlet temperature by controlling the mixed air volume. If you adjust the temperature to a higher temperature, the air conditioning system will send part of the cool air to the warm air tank to be heated and then mixed with the cold air. In this way, the temperature of the air outlet will not be so low, which actually wastes part of the cooling power. Variable displacement compressors can regulate temperature by reducing compressor operating power.
Therefore, for a fixed displacement compressor, the temperature should be adjusted to the lowest to save fuel. The higher the temperature is adjusted for a variable displacement compressor, the more fuel-efficient it is.
